1. FIELD OF THE INVENTION
The present invention relates to an oximeter device for measuring the oxygen saturation degree in arterial blood.
2. DESCRIPTION OF THE PRIOR ART
There has been proposed a probe calibration device of an oximeter device titled "CALIBRATED OPTICAL OXIMETER PROBE" (referred to as First Prior Example hereinafter) in the U.S. Pat. No. 4,621,643. The first prior example is characterized in that the probe device which is used together with the optical oximeter body for obtaining data of blood of a patient comprises;
light emitting means for emitting light of a known narrow wavelength range, a photosensor for detecting the intensity of the light passed through a patient to be measured, a coding means for applying the data signal of the known narrow wavelength to the optical oximeter body with respect to the probe and a connection device for attachably and removably attaching the coding means, the photosensor and the light emitting means to the oximeter body,
whereby the oximeter body receives the data signal at the coding means so as to determine the frequency of light emitted by the light emitting means, and subsequently calculate the oxygen saturation based on the determined frequency.
There has been proposed a general organism data measuring device (referred to as Second Prior Example hereinafter) in the U.S. Pat. No. 4,418,392. The above mentioned organism data measuring device measures the data of the organism and comprises;
a transducer for measuring an organism data to be required and for converting the organism data into a corresponding electrical data,
a memory means for storing a calibration data calculated in accordance with the reference characteristic of said transducer,
a calibration means for calibrating the converted organism data based on the calibration data,
a reading means for reading out the calibration data stored in the memory means, and
a calibration control means for controlling the reading means to read out the calibration data and selecting a corresponding part of the calibration data to the organism data measured by the transducer, and for controlling the calibration means to calibrate the converted organism data in accordance with the selected part of the calibrated data.
In the above mentioned first prior example, the light of a predetermined wavelength radiated from the light emitting means is applied to the photosensor through the examined organism and the output of the photosensor is processed by a predetermined calculation so as to calculate the oxygen saturation degree Sa0.sub.2 in the arterial blood of the organism. But, for example, in case the light emitting means emit not only the light of a narrow wavelength range but also the light of a comparatively wide wavelength range or emit a light of another wavelength than the main wavelength (referred to as the light of a sub-wavelength), there occurs an error in the calculation value of the oxygen saturation degree Sa0.sub.2. Moreover, in case two light emitting means, for example, are used in order to calculate the oxygen saturation degree Sa0.sub.2 and the light emitting spectrums of the two emitting devices are overlapped with each other, or in case each data of the light emitted by the above mentioned two emitting means is mixed in the process of the calculation of the oxygen saturation degree Sa0.sub.2 and can not be obtained separately at the output of the processing circuit of the above mentioned calculation so that crosstalk exists, there has been a problem that there occurs an error in the calculation value of the oxygen saturation degree Sa0.sub.2.
Furthermore, the latter second prior example comprises a calibration means for performing the calibration process of the calculation data at the time of calculating the data of the organism, but the concrete means or ways of calculating the oxygen saturation degree are not disclosed.